Apparatus and method for repairing worn rail shoulders

ABSTRACT

In a railroad system a track is formed of ties positioned at predetermined intervals along the right of way, and supporting a pair of rails. Shoulders are disposed in pairs adjacent to the sides of each rail and are partially imbedded in the ties to limit the lateral movement of the rails and define the track gauge. Between each pair of shoulders there is provided a pad disposed under the respective rail. Insulators are provided between the sides of the pad and a respective shoulder. Over time, friction between the insulators and the shoulders may cause excessive wear. This wear is compensated by one or more shims attached to the shoulders by a strong adhesive.

RELATED APPLICATIONS

None

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention pertains to a method and apparatus for repairing shoulders attached to railroad ties and used to hold rails in place, and more particularly, to a method in which a clip is attached to a face of the shoulder to compensate for material worn away by extended wear and tear.

2. Description of the Prior Art

Railroad systems are still used in many parts of the world as a primary means of transporting freight and people. In a typical modern railroad system, the rails are supported on concrete ties by a pad positioned between two iron shoulders. More specifically, a resilient pad is disposed between the shoulders on the ties, with plastic insulators being coupled to the pads and abutting each of the shoulders. The pads are resilient to protect the ties and to provide a smoother ride for the train and to compensate for slight size and position variations of the ties. As each of the wheels of a moving train passes over each of the ties, the weight of the train causes the rail to travel slightly downward on the pad, causing the sides of the plastic insulators to rub against a face of the shoulders. Over time, this action is repeated sufficiently to cause wear and te3836-018final.docar of the shoulder face. This erosion is increased when sand and other abrasive particles are lodged between the sides of the plastic insulator and the shoulder face. The same action also produces a wear and tear effect on the sides of the plastic insulators as well. The erosion of the shoulder face and the sides of the plastic insulators can be sufficiently large to allow the pad disposed between two adjacent shoulders, and the rail disposed therebetween to shift laterally. This lateral shift can be, in some instances, sufficiently large to cause the gauge to be too wide to meet the standard railroad specs.

This problem must be corrected by eliminating the effects of wear and tear on the plastic insulators and the iron shoulders. Plastic insulators are designed to last as long as rail sections and therefore it is relatively easy and simple to replace the plastic insulators (and the pads, if necessary) at the same time as the rails. However, the iron shoulders are embedded into the concrete ties and cannot be removed therefrom. Therefore, until now, the only way to correct for excessive wear of a shoulder face is to replace the entire tie. Needlessly to say, replacing concrete ties is very expensive, and time consuming. In the present invention, an alternate means and method are provided to repair iron shoulders with worn front faces.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a somewhat diagrammatic plan view of a typical section of railroad track with several ties;

FIG. 2 shows a plan view of a rail support used on the track of FIG. 1 with a shim constructed in accordance with this invention;

FIG. 3 shows an enlarged view of a shoulder receiving a shim in accordance with this invention;

FIG. 4 shows the face of the shoulder used in FIG. 3;

FIG. 5 shows a front view of the shim being applied to the shoulder of FIGS. 1-4; and

FIG. 6 shows a flow chart of the present process.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIG. 1, a typical railroad track 10 consists of a several ties 12 disposed on the grade along the track bed. Each tie holds two rail support assemblies 14, for supporting two parallel rails 16, 18. The rails 16, 18 are shown only in outline. Detail of the rails and many additional components such as clips securing the rails 16, 18 to the support assemblies 14, and other well known components have been omitted for the sake of clarity. The ties can be made of concrete. Moreover, in some instances, rather then providing a single tie extending under both rails 16, 18, individual tie segments may be used, with one tie segment being disposed under each rail.

As shown in more detail in FIG. 2, each support assembly 14 includes two shoulders 20. The shoulders 20 are made typically of iron and have one or two mounting legs (not shown) imbedded in the ties.

The two shoulders 20 are carefully placed with respect to each other to define an exact space L between them. In addition, the two support assemblies 14 on each tie are carefully placed at an exact distance from each other to define the distance between the rails 16, 18 and thereby define the gauge of the track.

A pad 22 having a general I shape is disposed between the shoulders 20 as shown. The pad is preferably made in one or more pieces and is resilient to provide cushioning for the rails. The pad 22 is preferably attached to the respective tie 12 using an appropriate adhesive. Pads of this type are disclosed for example in commonly assigned U.S. Pat. No. 7,080,791 incorporated herein by reference. Of course, other types of pads may be used as well.

The pads 20 have two lateral cutouts that house corresponding insulators 24. The insulators are made of an electrically insulating material and are provided to provide electrical isolation between the shoulders 20 and rails 16, 18. The insulators 24 are normally attached to the pad 22 and are in contact with the front face 26 of the respective shoulder 20. As a result, as discussed, each time a railroad wheel rolls over each pad 22, the pad 22 gets compressed vertically causing a vertical movement of its insulators 24. Since the insulators 24 are in physical contact with respective shoulders 20, after a while they wear portions of the face 26 away and cause a gap ‘g’ to form between the face 26 and the respective insulator 26. (See FIG. 2). As discussed above, the positions of the shoulders 20 define the gauge of the track. Once gap g is formed, the pad 22 can creep laterally toward the shoulder thereby increasing the lateral spacing between the rails 16, 18 sufficiently so that this distance may exceed the nominal gauge of the track. However, until now the only way to overcome this problem was to replace the whole tie with a new tie and new shoulders.

According to the present invention, a worn shoulder is repaired using a shim 30 sized to fit over its face, as indicated in FIG. 2. More particularly, as shown in FIGS. 3 and 4, a typical shoulder 20 is formed with a body 30 forming a horizontal platform 32 between two walls 34, 36 which are angled toward each other as they approach face 37. The body 30 is also formed with two lateral wings 38, 40. As previously discussed, the shoulder 20 also includes one or two legs (not shown) that extend downwardly and are set into the concrete tie for mounting the shoulder 20.

As shown in FIGS. 1 and 2, the face 37 comes into contact with an insulator 24 on pad 22. Over time, as trains pass over the support 14, the movement of the insulator 24 causes the face 37 to wear off. This action is further aggravated by sand, and other extraneous matter that collects between the face 37 and insulator 24 and act as an abrasive therebetween.

In the embodiment shown, the shoulder 20 is formed with an upright extension 42 having a generally triangular cross-section. It should be understood that the shoulder described herein is just one of many different types of shoulders that are presently available from different manufacturers. Other shoulders may have slightly different shapes and sizes then what is shown herein.

In order to resolve the worn shoulder problem, a shim 60 is provided. Preferably the shim is made of a thin steel plate having a uniform thickness, but can be made from other materials as well. The shim 60 is shaped to match the shape of shoulder front 37. Typically the shim 60 may have a thickness of about 1/16-⅛ in. As shown in FIGS. 3 and 5, the shim 60 includes a body 62 formed of a straight central segment 64 and two lateral wings 66. In the configuration shown in FIG. 3 the face 37 has rounded sides 44, 46, said sides being in the shape of a partial cylinder with a vertical axis of curvature. For this shoulder, the wings 66 are curved to match the curvature of sides 44, 46, as shown. One or more tabs 68 are also provided which extend over the platform 32. In the figures, two tabs 68 are provided, one on each side of extension 42. However, if a shoulder does not have an extension, then a single tab 68 can be provided that is wide enough to extend across the width of the platform 32, or three or more tabs 68 are used.

The shim 60 is held in place by an industrial-strength epoxy or other strong adhesive material. Preferably, the epoxy must be weather proof since the track systems are frequently installed in locations that are subjected to inclement weather conditions with large temperature and humidity ranges. One such material is available under the name of SRP 210 or Spikefast Polyurethane available from Willamette Valley Company, Eugene, Oreg. Other adhesives may be used as well.

In one embodiment of the invention, the shim 60 is applied in place using the epoxy to hold in place. However, a better practice is to remove the pad 22 before installing the shim 60. This process is performed as illustrated in FIG. 6. In step 100 the clips (not shown) holding the rails 16, 18 are removed. In step 102 a portion of the rail (16 and/or 18) is cut and the cut rail portion is removed. In step 104 the supports 14 are removed, including the pads 22 and insulators 24 are removed. In step 106 the ties 12 and the shoulders 20 are thoroughly cleaned and dried, using a blow torch, if necessary.

In step 108 all the worn shoulders are identified. In step 110 at each affected tie, a shim is provided and epoxy is deposited on the shim and the shim is attached to the shoulder (step 112). The amount of the epoxy 70 used (see FIG. 3) can depend on the actual wear of the shoulder. Naturally, more epoxy 70 is used for shoulders with more wear. If necessary, the shims are heated to set the epoxy (step 114). Then in step 116 new pads and insulators are installed, if necessary, unless the old ones are good enough. As part of this step, a lubricant such as white lithium grease may be applied between the insulator 24 and the shoulder face 37 to reduce friction, retard mold formation, etc. In step 116 a new rail segment is positioned on the rail supports 14 and installed, clips are installed to hold the rail segment in place (step 120) and finally, in step 122 the ends of the rail segment are welded to the adjacent rail segments.

The process described in conjunction with the flow chart of FIG. 6 is particularly advantageous at locations where several adjacent shoulders need repairs, or where a segment of rail needs to be replaced or reconditioned anyway as normal part of maintenance. In an alternate embodiment, e.g., where only one or two shoulders need repair, an abbreviated procedure may be used. In this procedure, the rail is unclipped from several ties (e.g., six ties) and then pulled away laterally from its supports. The pads and insulators are removed, the ties and shoulders are cleaned, the shims are installed on the shoulders with epoxy, and the rail is pulled back to its original position. The rail can be shifted laterally back and forth either manually or with a hydraulically assisted device.

Numerous modifications may be made to this invention without departing from its scope as defined in the appended claims. 

1. In a railroad track system comprising a plurality of ties and rail supports including shoulders imbedded in the ties and having fronts and support elements disposed adjacent to and touching said front, wherein trains running over the rail causes the support elements to rub against, and wear away said rail surface, said method comprising: providing a shim; and attaching said shim to said face with an adhesive.
 2. The method of claim 1 further comprising removing a section of the rail from the supports prior to the step of attaching said shim.
 3. The method of claim 1 further comprising heating said shim after said shim is attached.
 4. The method of claim 1 wherein said shim is attached using an epoxy.
 5. The method if claim 1 wherein said shim is made of sheet metal.
 6. The method of claim 5 wherein said shim is made of steel.
 7. The method of claim 1 wherein said face has a predetermined contour and said shim is formed in a shape complementary to said contour,
 8. The method of claim 1 wherein said rail is moved laterally without cutting its ends to repair said shoulder.
 9. The method of claim 1 wherein a portion of said rail is cut before said shim is installed.
 10. A method of rebuilding a portion of railroad track, said railroad track including at least one rail, a plurality of ties disposed in sequence along the railroad track, each tie including a pair of shoulders provided to restrict the lateral movement of the rail along the tie, the system including a pad disposed on each tie under the track and an insulator disposed adjacent to a surface of one of said pairs of shoulders, wherein trains moving along the track cause the insulator to rub against a face of the shoulder thereby wearing a portion of said shoulder away, the method comprising the steps of: removing clips from a rail portion; cutting the portion of the rail at its two ends; removing the portion of the rail with cut ends; removing the pad and the insulators disposed under the removed rail portion; identifying a shoulder that has a worn face; installing a shim on the worn face using an adhesive, said shim being positioned and arranged after it is installed to compensate for the worn portion of the face; installing a pad with insulators between shoulders, including the shoulder with the shim; and installing a rail portion over the pads.
 11. The method of claim 10 wherein the removed pad and insulator are reinstalled.
 12. The method of claim 10 wherein new pad and insulator are installed after the shim is attached to the shoulder face.
 13. The method of claim 10 further comprising applying and adhesive between said insulator and one of said shim and said shoulder face.
 14. The method of claim 10 wherein said shim is made of sheet metal and bent to a shape matching the shape of the shoulder face.
 15. In a railroad system, a track disposed along a right of way, said track comprising: a plurality of ties; a pair of rails; a plurality of rail supports supporting said rails on said tracks; wherein each rail support including a first and a second shoulder having a shoulder face with a face profile, a pad disposed between said shoulders under one of said rails and a first and second insulators disposed adjacent to said pad, and a shim disposed between one of said insulators and the corresponding shoulder face, said shim having a shape selected to match said face profile and being attached to the respective shoulder face by an adhesive.
 16. The track of claim 15 wherein said face profile includes a central face portion and two lateral rounded sides having a curvature and wherein said shim has a central shim portion and two lateral wings with a curvature selected to match the curvature of the rounded sides.
 17. The track of claim 16 wherein said rounded sides have vertical axes of curvature.
 18. The track of claim 16 wherein each said shoulder includes a flat platform terminating at said central face portion and wherein said shim has a tab dependent on said central shim portion and sized and shaped to extend over said platform as said shim is attached to the shoulder.
 19. The track of claim 16 wherein said shim is sized and shaped to compensate for the wear of the front profile caused by previous direct contact between said shoulder face and the respective insulator. 